Dave wrote:
"Cecil Moore" wrote:

Owen Duffy wrote:
This has nothing to do with the stated myth: Measurements with a Bird
43 of the conditions on the Thruline section are invalid unless it has
some minimum length of 50 ohm line on both sides of itself.

Would you be willing to make the same statement about an MFJ wattmeter?

now your are just trying to muddy the waters... i wouldn't trust an mfj to
measure anything!

No, I'm just trying to get back to the original discussion which
was: Do SWR meters need 50 ohm coax surrounding them to establish
the assumed 50 ohm environment? The majority of SWR meters have
no Thruline and MFJ seems to make no attempt to establish a 50
ohm environment like Bird does. What is the Z0 of a meandering wire
surrounded by an aluminum box?

The original discussion (V/I ratio is forced to Z0) had nothing to
do with Bird wattmeters. The original discussion was about SWR meters
in general (which the Bird is not). The mythbusters thing was an
interesting diversion away from the original question which remains
unanswered.
--
73, Cecil http://www.qsl.net/w5dxp